Berulfsen, B., & Boardman, P. (1964). Elementary Norwegian: Draft of an audio-lingual method. University of Oslo International Summer School.
Citazione stile Chigago Style (17a edizione)Berulfsen, Bjarne, e Philip Boardman. Elementary Norwegian: Draft of an Audio-lingual Method. Oslo: University of Oslo International Summer School, 1964.
Citatione MLA (9a ed.)Berulfsen, Bjarne, e Philip Boardman. Elementary Norwegian: Draft of an Audio-lingual Method. University of Oslo International Summer School, 1964.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.